1. Field of Invention
The present invention relates to a pixel driving circuit, and more particularly, to the pixel driving circuit of an organic light-emitting diode
2. Description of Related Art
In the conventional display device, the power source uses the wire to provides the voltage to the driving circuit; however, since the wire itself has the impedance, hence, the terminal end of the wire will inevitably have the problem of voltage degradation, and this phenomenon will cause the decrease of the driving current of the pixel of the organic light-emitting diode, such that the display device provides images with uneven brightness. With the development of technology, display devices with larger sizes are being developed, and the above-mentioned phenomenon is particularly severe in larger display devices.
Moreover, since the transistors used in the pixel driving circuit of the organic light-emitting diode are not exactly the same, hence, the manufacturing processes and component characteristics thereof are also different, and when the manufacturing processes are different or when other factors are different, it will result in the difference of the threshold voltages of the transistors; in this way, it also causes the uneven brightness of the display device.
Further, the life cycles of the components of the organic light-emitting diode are limited, and hence, the characteristics of the organic light-emitting diode will gradually degrade with the passage of the display time, which phenomenon will also affect the brightness of the organic light-emitting diode, thereby resulting in the uneven brightness of the display device.